Grinding machine



Dec. 12, 1933. 3q w HOPKlNS 1,938,766

GRINDING MACHINE Filed Aug. 18, 1930 4 Sheets-Sheet 2 /7 immun CEc/L W HUP/N5 Dec. 12, 1933. v c. w HOPKINS GRINDING MACHINE Filed Aug. 18, 1930 4 Sheets-Sheet 3 Syvum/C01 CEc/z. W HUP/UNS Dec. l2, 1933. c. w. HOPKINS 1,938,76

GRINDING MACHINE Filed Aug. 18. 1930 4 Sheets-Sheet 4 31 l 55 8M wom/toc 34 16T/'7 7 CEc/zJ W HoF/W5 5&1 WVM/0714- Mula,

Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE GRINDIN G MACHINE Cecil W. Hopkins, Cincinnati, Ohio, assigner to Cincinnati Grinders Incorporated, Cincinnati, Ohio, a oorporationof Ohio f `Application VAugustV is, 1930. serial No. 475,929

16 Claims.

This inventionrelates to improvements in machine tools and especially to improvements in centerless grinders.

objects of the present inoperations on taperedl or other formed work pieces.

Another object of the invention is the provision of a centerless grinder for performing grinding operations on successive formed work pieces thereby reducing idle minimum and increasing the production to theV maximum.`

in a substantially continuous stream time of the machine to a Another object of the invention is thel provision of improved means for feeding, positioning and discharging work pieces from the grind.

ing throat of a centerl ess grinder.

Another object of the invention is the provision of a centerless grinder forV the production of work pieces that is automatic in its action requiring nor attention of the operator other than supplying additional w or hopper.

ork pieces to the magazine ing a part thereof, and

it is to be understood that any modifications may be made in`A the .exact structural details there shown without departing from or exceeding the defined Vin the claimsV appended hereto.v

In the drawings:

spirit of the invention as Figure 1 is-an elevational view of a grinding machine embodying the improvements of this invention.A

Figure 2 isa top plan view ofthe device shown in Figure 1.

Figure 3 is an enlarged fragmentary sectional view taken on line `3 3 of Figure 2, showing the grinding throat with the work supplying means in position.

Figure 4 is a view takenloxiiine 4 4 of Figure 1, certain parts being section.

in elevation and other in Figure 5 is a sectional view ltaken on line 5-5 of Figure 4.

Figure 6 is a sectional view taken on line 6-'-6 of Figure 4. Figure 7 isa section of Figure 2.

al view taken online 7--7 Figure 8 is a sectional view taken on line 8-8 0f Figure 7.

y is likewise vmovable longitudinally of the bed 1li Figure 9 is a sectional of Figure 8.

Figure 10 is a sectional view on line 10-10 of Figure 8.

`Throughout the several views of the drawings similarA vreference characters are employed to denote the same or similar parts.

A device embodying the improvements of this invention may comprise a bed or support 10 sup- Y porting for rotative movement at a high or grinding rate of speed at one end thereof a grinding wheel 11 rotatable in a clockwise direction as indicated by the arrow on its housing. Opposed to the grinding wheel 11 is a regulating wheel 12 rotatably supported by regulating wheel unit 13 for rotation in a clockwise direction at a slow work controlling rate of speed.` The opposed surfaces of the wheels 11 and 12 form view taken on line 9-9 therebetween a grinding throat adapted to receive a work piece therein for simultaneous acu tion thereon'by the said Wheels. The regulating Wheel unit 13 is integral with a slide 14 movable on ways 15 formed on the upper surface of a second or lower slide 16. The said lower slide 16 0 on ways 17 formed on the said bed. Cla'mps 18 and 19` are provided for respectively securing the upper slide 14 to the lower slide 16 and the said lower slide 16v to the bed. Translation of the said `slides is accomplished through an ad-V justvingy screw 20 rotatably journaled in a housing 21-and having on its outer end a pilot or yhand wheel 22. The threads of the screw 20 engage with a nut -231carried by the unit 13. The said slidesv 14 and 16 are adjusted by the pilot or hand wheel 22.to position the wheels 11 and 12 relative to one another to provide a grinding throat y of the desired size at the time the machine is bejacent the grinding throat a work` supporting table l27 which is intermediate the grinding throat and the` feeding mechanism mounted within housing 28. and likewise carried by the block 24. 0n thev other `side of the grinding throat-.supported by the block 24, is the stop orv work limiting mechanism carried by the bracket .As shown in Figure 3, the work carrying mechaficientto permit the movementf of-thelo'vver most iWork. piece thereunder-:but: preventanyl ably secured to vertical brackets 35. 'Iheangle irons 33 and 34 are each provided with elongated perforations 36 vso that the said angle irons may be adjusted toward and from the vertical wall 32 to vary the capacity of the magazineyBe-l neath the magazine is an angled top f support 37 carried by the block 24 andinfsubstantial alignment with the angledtop` 26 of .the-work.

rest blade 25.` y

The work feeding mechanism within the housing 28 comprises an oscillat'able arm 38 mounted for movement about a sleeve 38a. loosely-mounted,

on and co-axial with the rock shaft 39. The said shaft 39 is `ikeyed or otherwise secured to. an

actuator 40 which has secured thereto oneendV`Y of= 1.a spring A- 42 havingits` other end connected with a pin 43 iixed to one wall of the-housing 28. vThe actuator 40 has an arcuatef slot141 formedtherein through'which a pin or bolt`v41a` passes for connecting .theactuator`40 Cand`arm 385. with one another in-various adjustments.

The upper end ofl the arm 38 lis forked to provide ngers 44 and.45, as seen in F'ig'ure',

straddling theguide member 46.. The fingers 44A and? 45 areeach in turn bifurcated to provide ears 47 and 48 between .which rollers `49 are received. Y The rollers 49 extend from opposite sides o'fthev guide 46and are rotatably mounted on pins 50 extending from block 51 vthrough elongated openings 52`formedin the sides-of guidelmember plunger 53 which hasinV its# forward-iendfa--ta- 'pered' socketr54receiving the.v taperedend orshank ofpush rod 55. Theplunger '53 'is 'guided'-l bybearings 56 mounted within guide sleeve 57 secured to. one endv of housing 28.y A closure'tubef 58 isthreadedly` carried by the' guide-"sleeve 57`v to protect Athe l operator-.and plungerlfrom injury.v

As seenfrom Figure 3,' the lowermo'st work. piece 59.=is lying on. the'support .blade-37 With'oneend of plunger rod abuttingsaine;4 as'rshown in Figure`4. Rocking oiv the actuator40, by means*v .y to. be. later described, 'will' oscilla'te'v `arm 38` and block 51.thereby` axially shifting plunger 53l and push vrod 55 to therear and loading--thespring'- 42. Subsequently .or at the. completion'oflthev the grindingoperation thevsaidfspr-ing 42 ex- `pands or res `for reversely, axiallyl shiftingfthe`r plunger 53. and push rod 55 for-injecting they said lovvermostl work 'piece into they grinding throatA ionto s the yangled face 36 'of v'vork're'str` blade25.. Thelower end'60` of sidebracket 35- '.-is spaced above the upper' surfaces-oi?'" suppdorty blade r37: and work rest blade 25 a distance sufmovement of the .next adjacent workpiece.

The. Work pieces are machined or finished-'With' ataperfrom one .en'd tothe'other for. which puri' pose.. the active face of. the regulating wheellisV taperedlan amount. double; the .taper "to-.bei formedv on thefsaid work thereby. permitting` the `grindin'g Wheelgtdhave a plane face. This -taperis ofv aV verysmall amountiand isnot shownin thedraW-v ingazit, being vno greater :than that-'produced` on twist.d111s and jthe .like,:withf which those con'-y In order to4 versant With this art are familiar. position the work.' properly; relative -f..to. .'thez. said faces of the wheels a stop or positioning mechanism is provided. AThis mechanism comprises the bracket 29 supporting a bracket 61 adjustably carrying an overhead guide shoe 62 adjustable by bolts 63 extending through elongated openings 64 into the bracket 61. The stop or positioning member`65 hasy a rack 66 extending therefrom. andA meshing with. anV elongated pinion 67.d The pinion 67 is fast on shaft 68 journaled in the walls of the bracket 29. A second rack bar 69 is provided and is adapted to be actuated in a plane at right angles to the plane of movementPof the rack 66 and the said rack 69 ,Vengages-withythe'pinion 67 for actuating said pinion.' The shiftingv movement of rack bar 69 is obtained: throughf an'. arm 70 having a sliding connection 4at 71 with a block 72 adjustably se- 'cured'to the bar'69.4v The said arm 70 is pivoted at 73 vtothe bracket 29 and is oscillatable thereabout by an actuating rod 74 slidably journaled in bearings 752an'd 76 extending fromthe block 24.1 AspringA 77nsurrounds .the actuating' rod 74'! abutting on one end with the bearing` 75' and oni the other end vwith 1the..co1la.r 78 vsecured to fthe rod 74. 'I'heshiftingmovement .is'impartedtorod-.74rby aftrigger 79. :keyed for movement with oscilla/tableA orlrock shaft80." 'Thesaid rock shaft L 80 is actuated in synchronized relation with/then rockashaft `39 'by` 4the 'mechanism lto be later described.

fAfterthe l'workpiece has beenxpositioned within the :grinding throat the.said.-throat is con-.f

tractedor restricted. as Yby actuating-.theregulatwheel to shift the work on the blade 25sinto the grinding wheel andteifecta stockfremovalthere- A from. :This movement is :accomplishedautomati- 46.r The block v451 -is .formed on the-'end offa .i

cally bythe mechanism Awithin housing 21 which' includes the Worm shaft 81;..having removably'secured onits one end-'a gear 82 coupled'through .L

havingv the cam groove v89 formed in' one face in whichrollerhQOlis"received; The roller 90 is. carriedfbyan adjustable block'f91l in turn secured to anfarrn 92 pivoted at 93 .to .the lwall ofthe housing 21?; The arm 92'fhas -a portion 94 extending above' the'p'ivot 93 `from which lugs 95y extend and have pivotedltheretov one. endy of. vlinks 96.r .The other end of links 96 are;v pivoted. to ia slideblock 97 slidable through.' Ibea'rin,.1,;.98 .and secured to the adjusting screw 20 as by collars-99.

From the foregoing? it Awillbe noted that rotation ofcamithrugh 'camgroove 89 effectsa rocking or oscillating movement of the arm 92494'. about thepivo't 93.-? This oscillating movement through the links 96 actuates the slide bloek19'7v and adjusting screw` axially relative to the bearings thereby actuating the regulatingl wheel unit 13*v and wheel -12toward Sandi-.fromfthe grinding Wheel. This movement is accomplished. 'through the sharp rise 1001whicheffectsvafrapidin-feed movement of :the uniti-*13 followedby vagrado-al rise from the point 101 to point 102 for-slowly feedingfthe work into l ther-grinding '.whe'el and then a concentric portion from point 102 to point 103 at 'which time the parts .are held relatively stationary to permit a sparking out ofthegrind-L ing--Lwheel andlthe vdesiredufinish .on the'iwork. A sharp decline from point 103 to point 1001 then comes.intoplayfi'onI rapidlyretracting the regulating wheel unit 13 to the work loading position.`

It is` when the said wheelis retractedA that. the nnished Work discharged from the grinding throat and an unfinished one placed therein.

This shifting of the work into and out of the grinding throat is performed in synchronized timed relationV with the movement of the unit through the rock shafts and 39. The said rock shafts, as shown in Figure 1, extend from the housing 28 to the housing 21 being journaled therein and actuated by the cam 88. The rock shaft 80 has its rear end journaled inthe wall of the housing 21 on whicha rack pinion 104 is secured for movement therewith. Meshing with the pinion 104 is a slidable rack bar 105 having a i lug 106 formed at one end thereof. One end 107 of a lever 108 engages with the lug 106 and has its other end pivoted atk 109 to a lug 110 carried by the wall of the housing 21. The. lever 108 has rotatably secured thereto intermediate its ends a roller 111 riding on the rear face 112of the cam 89. A cam portion or lug 1-13 is formed on the said face 112 for engaging the roller 111 and actuating arm 108 about its pivot 109.

The forward face 113 of cam 88 is provided with a depression 114 for receivinga roller 115 riding on the saidv face 113. This roller 115 is carried by the inner end of sliding rack bar 116 which has its teeth meshing with rack pinion 117 journaled in a bracket 118 extending, from the housing 21. sliding bearing for the sliding rack bar 116 as well as forms the bearings for oscillatable shaft 39.

The cam portion in cam groove 89 between the points 103, 100 and 101 and the depressed cam portion 114 on one face of the .cam 88 and the cam lug 113 on the other face thereof are so related that the depressed portion of the cam 103-101 first retracts the regulating wheel unit from the grinding wheel whereupon cam lug `113 actuates the arm 108 for rocking shaft 80 and raising stop 65 out of the path of the work piece within the grinding throat and then the cam depression 114 aligns with roller 115 when spring 42 will rock the shaft 39 forcing the said roller 115 into the,

depression 114 thereby axially shifting plunger 53 and push rod 55V for shifting the lowermost vwork piece in the magazine into the grinding throatl yroller 111 and the'spring'i'i which surrounds the rod 74 having been compressed or placed under tension during the raising of the abutment member 65, now expands and lowers said abutment into the path of movement of the unfinished work piece being placed within the grinding throat by the pusher 55 to position saidwork relative to the wheels. As soon as the work piece has been properly positioned the roller115 is ejected `f rom the cam depression 114 by the walls thereof and the rod 116 through the rack and pinion connection rock the rock shaft 39 in a counter-clockwise direction for withdrawing the pusher 55 from the grinding throat and loading the actuating spring 42.V This retractionof the pusher 55 permits the lowermost work piece in the magazine to fall onto the support blade 37 in the path of movement of the pusher 55. K At the Vsame time or during the,v

retraction of the pusher4 55 the* camV 88 has advanced to theposition for the rapid infeed of the regulating wheel 12 and slide 14 toward the grind- The said bracket 118 supports the l ing wheel to initially feedthe work into the grindingwheel whereupon the further movements of the regulating wheel unit are under the control of cam 88, as above described, until the completion of the grinding operation. l i

, From the foregoing it will be noted that an automatic form grinding machine has been provided whereby the only attention necessary by the operator lis the placing of unfinished work pieces or blanks on the inclined table member 30 which pieces, under the influence of gravity, roll downr pushing ahead of it the finished work piece thereinv whereupon. the stop mechanism finishes the positioningwof the work piece relative to the active face of the wheels. After the work has been positioned the grinding throat is retracted to feed the said work into the grinding wheel and effect a stock removal therefrom whereupon the throat is widened and a recurrence of the loading cycle automatically initiated.

It will be noted that the work is yieldingly fed into the grinding throat so that should an obstruction enter the path of the work 0r a Yjam occur no breakage or damage to the parts will result since the feeding-will be held in abeyance against the yielding action of the feeding spring 42.

What is claimed is:

1. In a centerlessV grinder the combination of a.v

pair of opposedgrinding and regulating wheels forming agrnding throat therebetween, awork rest blade within the grinding throat for supporting work pieces in simultaneous engagement with4 the said wheels, a magazine for holding work piecesexteriorly of the grinding throat'in alignment therewith, means for axially individually shiftingv the work pieces from the magazine into the grinding throat, said axially shifted work piece displacing the finish work piece .within the grinding throat, and means co-operatin'g with the work rest blade for positioning thework relative to the wheels but movable relative to the blade to permit the finished work to pass thereunder while being discharged from the grinding throat.

2. In a device of the .class described the combinationof a bed or support, a pair of opposedgrinding and regulating wheels carried thereby and forming a grinding throat therebetween, a work rest blade within thevth'roat and supporting work while in engagement with the wheels, r, magazine adjacent the throat exteriorly thereof, a Asupport member beneath the magazine in alignment with the work rest blade, means operable toward the grinding throat for shifting the lowermost work piece from the magazine support onto the work rest blade, abutment means for engaging the work to position same relative to the work rest blade, andmeans for shifting the abutment means out of the path of the work to permit the said work to pass thereby as it is being discharged from the grinding throat.

3. In a device of the class described the combination of a bed or-support, a pair of opposed vgrinding and regulating wheels carried thereby and forming a grinding throat therebetween, a workrest blade within the throat and `supporting work while in engagement with rthe wheels, a magazine adjacent the throat exteriorly thereof, asupporting member beneath the magazine in alignment, with the work rest blade, means opthe lowerniost Work piece for'r'ithe-xagaz'inesupp'rt o'ntlth Wrkrst blade; Vabiitnien'tfinear'is for engaging the work tof position same relative to ther work rest b1ade,ineaifis"forr actuating o'ne of the' Wheels toitr'dand frorn'the"ther-t'oeffect astbck removalfrorn the work-Within theI grind-v in "said throat; and means operable in! time relation withy the movement of saidy wheel' for retraetingl the abutment meansfrom the path of movementof ther Work-asy itislbeing discharged from the grinding throat.y

4. In a centerlessgrinder forv Vautomaticallyv grinding formed ywork pieces v'or the like com# prising opposed grindingand regulating wheels forming au grinding throat therebetween, a Work reist blade Within the -thrdat supporting Work pieces in engagement with the said: grinding and regulating Wheels, means for axially' feeding unnnlshed vwork into position betvy'eganl the'said wheels on thev Work restebladeandtfor axiaily discharging the finishedwo'rk from said blade,

sitioning the said unfinished Work relative to --work pieces relativete the grinding vthroat exteriorly thereof, Ya pusherabntting saidV Workr and pushing same vinto the grinding' throat, an abutment aligned witlrthe4 gi'inding throat limitingrthe movement of the work through the throat, and meansretracting the abutment out ofthe line of movementrof the work to permit the discharge of the work piece'from the tlirroat by the pusher4 6; An abutment mechanism for positioning Work pieces relative to the'work rest' blade of a centerles's grinding Athroat comprising av bracket,

' a stop block carried by the bracketand movable relative thereto,` means for positvelyraising the' stop block rom'the Vpath of vmovenl'entofithe wol-l; to permit discharge of the Work from theV grinding throat, andyieldi'ng means for'returning the stop" block to its operative position` forY positioning a succeeding Workpie'ceumi f y 7. In' a centerless grinder theco. bination'of a pair of opposed grinding and regulating Wheels forming a grindingthro'at therebetween, a Workv rest for supporting workpieces."Within thegrind-Y ing throat; means'for moving'one of `said Wlfleels toward the other to feed thefwork piecefinto Ythe" grinding Wheel, means for axially'jshifti'ng work pieces into the grinding throat Yand axially eject-f' ing themV therefrom, an abutment member for engaging the Work shifted int o' ther-grinding" throat for positioning same relative tol the Wheels but' retractable from the ,path of movement of the" Work to 'permita discharge ofthe Work from' the grinding throat, anda single'carn member for actuating saidpartsintirnedsequential or- 8*. Inv a'device of Athe class described the comi bination with means for feedingwork'pecesinto and through the throat of a centerless grinder, of an abutment shoe for'p'ositi'oning the work relative tothe throat, a' rack bar extending from the'shoe, a rack pinionjme'shing With'th'e rack bar, a secondrackbar engaging the rack pinion,

andjieas for@setuatihgithesecond racli'b'sf and pinion-'connection thereof -out off the path of' movement of the workbeing discharged; I l 91 In a deviceof the class described the com'- hina-tion with means for feeding work piecesint and Atli'rilgh the throat' 0f a centrle'sS grinder;-

ofari-abutment rshoe for positioning the Work relative to the throat, a rack bar extending'f'rom the shoe,Y` a rack pinion meshing-With thejraek bar, a secondv raok'barengaging the' rack pinion', means for actuating the second rack-bar andraising the" abutment shoe through vthe rack and of an abutment shoe for positioning the' work' relative to the throat, a rack bar extendingfrn the shoe, a rack pinion meshing with the rack bar, la second rack 'bar vengaging thev rack pinion; means for actuating the* second rack bar and raising the abutment shoe through the rack-and pinionconnection thereof out of the path of moveinen't'of thework'f being discharged, saidmeans comprising a rock shaft a sliding shaft, an op'- erative connection between' the rock shaft and sliding shaft for actuating the latter by the formen-'and apivoted arm operatively connected with the secondf'rackv bar and actuatedfby the sliding f1 shaft for adjusting said second rackV bar and elevating the abutment shoe.

1 1. AIn a device of the class described the combination'withmeans for feeding Work piecesl into and through the throat of a centerless grinder, of an abutment shoe for positioning thejwork relative toL the throat, a Yrack barextending from the shoe, a rack pinion meshing vwith the rack bar, a'fsecondA rack bar engaging the rack pinion, means'for actuating the second rackv bar and raising theabutment shoe'through'the rack and pin*- ion connection thereoffout of the path of Inovement of the Work being discharged, said means.y comprising a rock shaft, aws'liding shaft, an operative connection between the rock shaft and sliding shaft for actuating thelatter by the former, a -pivoted arm operatively connected with the second rack bar'and actuated by the slidingishaft for' adjusting said second rack bar and elevating the abutment shoe'and yielding means surrounding the 'sliding shaft adapted to-be tensioned by themovenientthereof for returning the abut-V nient'k to its normal position afterV discharged! the'workl.- l l l12. In a'centerles's grinder the combination' of abedf'a pair of opposed grinding'land regulating Wheels forming a grinding throat therebetween, a work rest blade Vsubten'dng the lgrinding throat and supporting kthe lwork-piece. in simultaneous engagement with the said wheels', one of said Wheels belng'l'rnounted for`V sliding movement toward and from the other Wheel, a `Vrnagaz'in'e eitteiiorly" yof thefgrindin'g' throat andA in alignrnentftherewith, a pusher member for shifting vyfprkl pieces from the magazine onto'the work restfblade,.anfabntrnent for engaging the lvirifsrkv piec'fa'n'd positioningitrelative to the Workl rest bladefa roollshaftfor actuating the pusher, a second rockshaft for'retrating the abutment member whereby the work piecemay pass thereby being ldischarged; from Athe work rest raising-the abutmentshoe' through the' rack-and blade, and a cam member for actuating the said movable wheel toward and from the remaining wheel and for actuating the rock shafts in time sequential order.

13. In a centerless grinder the combination of a bed, a pair of opposed grinding and regulating wheels carried thereby and forming a grinding throat therebetween, a magazine for holding a supply of work pieces, a work rest blade within the grinding throat and aligned with the lower extremity of the magazine, a pusher for shifting the lowermost work piece from the magazine onto the Work rest blade, an abutment within the grinding throat for positioning the work rest blade relative to the throat, a rock shaft for actuating the pusher, a second rock shaft for retracting the abutment member to permit workV pieces to pass thereby, and an operative coupling between the said rock shafts whereby they are actuated in time sequential order for first retracting the abutment member and subsequently shifting the new work piece onto the Work rest blade and ejecting the finished work piece from the blade past the abutment.

14. In a centerless grinder the combination of a bed, a pair of opposed grinding and regulating wheels carried thereby and forming a grinding throat therebetween, a magazine for holding a supply of work pieces, a work rest blade within the grinding throat and aligned with the lower extremity of the magazine, a pusher for shifting the lowermost work piece from the magazine onto the work rest blade, an abutment within the grinding throat for positioning the work rest blade relative to the throat, a rock shaft for actuating the pusher, a second rock shaft for retracting the abutment member to permit work pieces to pass thereby, an operative coupling between the said rock shafts whereby they are actuated in time sequential order for first retracting the abutment member and subsequently shifting the new work piece onto the work rest blade and electing the finished work piece from the blade past the abutment, and means for returning the abutment to its normal position for engagement with and proper positioning of the work piece being shifted into the grinding throat.

15. In a centerless grinder the combination of a bed, a pair of opposed grinding and regulating wheels carried thereby and forming a grinding throat therebetween, a magazine for holding a supply of work pieces, a work rest blade within the grinding throat and aligned lwith the lower extremity of the magazine, a pusher for shifting the lowermost work piece from the magazine onto the work rest blade, an abutment within the grinding throat for positioning the work rest blade relative to the throat, a rock shaft for actuating the pusher, a second rock shaft for retracting the abutment member to permit work pieces to pass thereby, an operative coupling between the said rock shafts whereby they are actuated in time sequential order for first retracting the abutment member and subsequently shifting the new work piece onto the work rest blade and ejecting the finished work piece from the blade past the abutment, means for returning the abutment member to its normal position for engagement with and proper positioning of the work piece being shifted into the grinding throat, means mounting one of said wheels for movement toward and from the other Wheel to feed the work and grinding wheel relative to one another and effect the stock removal from the work, and a cam member for retracting said wheel and holding same in a retracted position during the operation of the abutment member and pusher. 1

16. In a centerless grinder the c ombinationv of- Ablade relative to the throat, a rock shaft for actuating the pusher, a second rock shaft for retracting the abutment member to permit work pieces to pass thereby, an operative coupling between the said rock shafts whereby they are actuated in time sequential order for rst retracting the abutment member and subsequently shifting the new work piece onto the work rest blade and ejecting the finished work piece from the blade past the abutment, means for returning the abutment member to its normal position for engagement with and proper positioning of the work piece being shifted into the grinding throat, means for mounting one of said wheels for movement toward and from the other wheel to feed the work and grinding wheel relative to one another and effect the stock removal from the work, a cam member for retracting said wheel and holding same in a retracted position during the operation of the abutment member and pusher, and an operable connection between the cam and rock shafts whereby they are actuated in oEcIL W. HOPKINS. 

